Problem: Simplify the following expression: $k = \dfrac{2p - 9}{4p + 2} - \dfrac{-6p - 18}{4p + 2}$
Solution: Since the expressions have the same denominator we simply subtract the numerators: $k = \dfrac{2p - 9 - (-6p - 18)}{4p + 2}$ Distribute the negative sign: $k = \dfrac{2p - 9 + 6p + 18}{4p + 2}$ Combine like terms: $k = \dfrac{8p + 9}{4p + 2}$